WorksheetFunction.T_Test method (Excel)

Returns the probability associated with a Student t-Test. Use T_Test to determine whether two samples are likely to have come from the same two underlying populations that have the same mean.

Syntax

expression.T_Test (Arg1, Arg2, Arg3, Arg4)

expression A variable that represents a WorksheetFunction object.

Parameters

Name	Required/Optional	Data type	Description
Arg1	Required	Variant	Array1 - The first data set.
Arg2	Required	Variant	Array2 - The second data set.
Arg3	Required	Double	Tails - Specifies the number of distribution tails. If tails = 1, T_Test uses the one-tailed distribution. If tails = 2, T_Test uses the two-tailed distribution.
Arg4	Required	Double	Type - The kind of t-Test to perform.

Return value

Double

Remarks

The following table represents possible values for Arg4.

If type equals	This test is performed
1	Paired
2	Two-sample equal variance (homoscedastic)
3	Two-sample unequal variance (heteroscedastic)

If array1 and array2 have a different number of data points, and type = 1 (paired), T_Test returns the #N/A error value.

The tails and type arguments are truncated to integers.

If tails or type is non-numeric, T_Test returns the #VALUE! error value.

If tails is any value other than 1 or 2, T_Test returns the #NUM! error value.

T_Test uses the data in array1 and array2 to compute a non-negative t-statistic. If tails=1, T_Test returns the probability of a higher value of the t-statistic under the assumption that array1 and array2 are samples from populations with the same mean.

The value returned by T_Test when tails=2 is double that returned when tails=1 and corresponds to the probability of a higher absolute value of the t-statistic under the "same population means" assumption.

Support and feedback

Have questions or feedback about Office VBA or this documentation? Please see Office VBA support and feedback for guidance about the ways you can receive support and provide feedback.